The formation of potato peel (PPeel)–based films is likely attributed to gelatinization of starch and denaturation of protein, which can rearrange by forming new intermolecular interactions and eventually coherent cast films. Thus, the film‐forming ability and properties are highly dependent on the concentration, temperature, and time, as well as the resulting degree of denaturation. The aim of this study was to investigate the influence of PPeel concentration (2%–7% w / w ) on the film‐forming properties as well as the structure and physicochemical properties of the resulting cast films. Therefore, microscopic imaging of microtome sections, Fourier transform infrared (FTIR) spectroscopy, and X‐ray diffraction measurements were performed to reveal differences in film structure that were related to differences observed in the physicochemical properties of the films, including barrier and tensile measurements. Microscopic and FTIR measurements revealed remarkable structural differences between 2%–3% ( w / w ) and 4%–7% ( w / w ) PPeel‐based films, resulting in significant ( p ≤ 0.05) differences in oxygen permeability (3.0–9.1 cm 3 m −2 day −1 bar −1 ), water vapor transmission rate (66.8–111.9 g m −2 day −1 ), and tensile properties. Tensile strength of PPeel‐based films containing 2%–7% varied between 2.1 and 6.0 MPa and elongation at break between 13.7% and 28.1%. Therefore, different mechanisms for the formation of PPeel‐based films containing 2%–3% ( w / w ) or 4%–7% ( w / w ) PPeel are proposed, reflecting a dependence between PPeel concentration and film formation. As a result, this study provides a fundamental understanding of the formation of PPeel‐based films, which have the potential to be used as edible or antimicrobial films/coatings or as oxygen barriers in bi‐ or multilayer packaging.
Miller et al. (Thu,) studied this question.